What objective measurements qualify as "High Fidelity"?

[Justdafactsmaam]

In that case you can tune the function and adapt the room, once you have an enough accurate function (or constant transfer if you want). Without that you’re lost

Sure. You have to deal with the room. My point was it’s a major part of the system not a throw away

If you don’t move from your listening position, you can neglect all extra dimensions when considering the resultant of all reflections. Is called on axis response and is 1-dimensional by definition of “axis”.

It sounds like you are saying the radiation pattern of the speaker is of no consequence. If so I very strongly disagree

 

[Miguelón]

Sure. You have to deal with the room. My point was it’s a major part of the system not a throw away

It sounds like you are saying the radiation pattern of the speaker is of no consequence. If so I very strongly disagree

Well, I can include as much elements as you want in an accurate function but is for simplicity that on axis anechoic response is the base to construct hi-fi.

Ideally the radiation pattern can be spherically symmetrical if you consider a moving listener.

Probably this is impossible, so I don’t consider such a pattern or any other one as part of the fidelity question. Even music instruments have a defined radiation pattern.

Is more practical to get a clean transfer function from elements that are linear and consider this the basis of definition. Room corrections, wide sweet spot, soundstage and other elements are more of an acoustics phenomenon than electric one.

 

[Justdafactsmaam]

Well, I can include as much elements as you want in an accurate function but is for simplicity that on axis anechoic response is the base to construct hi-fi.

I just want the ones that matter

Ideally the radiation pattern can be spherically symmetrical if you consider a moving listener.

Not so sure that’s ideal. It will depend on the speaker/room interaction. The room is a big part of the system

Probably this is impossible, so I don’t consider such a pattern or any other one as part of the fidelity question. Even music instruments have a defined radiation pattern.

It is if we are concerned about what we actually hear. Radiation pattern and room interaction are a huge aspect of fidelity

Musical instruments are used to make music not accurately reproduce recordings. “Accuracy” isn’t even a quality of live acoustic music

Is more practical to get a clean transfer function from elements that are linear and consider this the basis of definition. Room corrections, wide sweet spot, soundstage and other elements are more of an acoustics phenomenon than electric one.

Yes but the question was regarding accuracy of the sound. Not the electrical signal

 

[sigbergaudio]

Well, I can include as much elements as you want in an accurate function but is for simplicity that on axis anechoic response is the base to construct hi-fi.

Ideally the radiation pattern can be spherically symmetrical if you consider a moving listener.

Probably this is impossible, so I don’t consider such a pattern or any other one as part of the fidelity question. Even music instruments have a defined radiation pattern.

Is more practical to get a clean transfer function from elements that are linear and consider this the basis of definition. Room corrections, wide sweet spot, soundstage and other elements are more of an acoustics phenomenon than electric one.

If you are saying you only consider on-axis response when evaluating fidelity, then you have not understood how loudspeakers work and/or how they interact with the room. The anechoic on-axis response is not sufficient information to evaluate loudspeaker quality.

 

[Miguelón]

I just want the ones that matter

Not so sure that’s ideal. It will depend on the speaker/room interaction. The room is a big part of the system

It is if we are concerned about what we actually hear. Radiation pattern and room interaction are a huge aspect of fidelity

Musical instruments are used to make music not accurately reproduce recordings. “Accuracy” isn’t even a quality of live acoustic music

Yes but the question was regarding accuracy of the sound. Not the electrical signal

I think you’re turning round. The thread is about measurements, spinorama and room response at different points/angles are only displacement transformations of the same ideal functions.

Is what in physics called “invariants” so are not really new measurements but the same.

To have an ideal hi-fi experience is the one you obtain in an optimal recording studio: negligible wall and furniture reflections, flat response, low distortion and adequate SPL

That’s all, the rest is imitate that with different levels of accuracy

 

[sigbergaudio]

I think you’re turning round. The thread is about measurements, spinorama and room response at different points/angles are only displacement transformations of the same ideal functions.

Is what in physics called “invariants” so are not really new measurements but the same.

So if two different speakers have identical on-axis response, it is your understanding that the off-axis responses will also be identical?

 

[Miguelón]

If you are saying you only consider on-axis response when evaluating fidelity, then you have not understood how loudspeakers work and/or how they interact with the room. The anechoic on-axis response is not sufficient information to evaluate loudspeaker quality.

Not the quality, but the accuracy of the gear. If you have perfect anechoic on axis response then you can work with that.

Not an enough condition but a necessary one. Room response doesn’t depend on the speaker, is not linear nor predictable (yes they are predicted room response curves but they fail by a huge amount).

In my proposition about how measurements should be taken by account, room response doesn’t change anything. You can take the same you use in anechoic chamber and repeat them.

 

[Miguelón]

So if two different speakers have identical on-axis response, it is your understanding that the off-axis responses will also be identical?

The thread is not about speakers but fidelity measurements.

I don’t consider spinoramas another measurement, just a graphic representation of many of on-axis ones taken on different angles.

The same about reflections: you cannot predict them, so there are not very useful.

I propose only SPL, FQ curves, harmonic distortion and noise as enough metrics. I can suggest also time dependent measurements to add, still referred to on axis anechoic.

Two speakers with same on axis anechoic response will sound different depending of the room, but consider the room it cancel the term “fidelity” as one room is different from another and there’s impossible to have an ideal to replicate (except the trivial one: anechoic).

So by limitations of environmental conditions, we should simplify and consider a high fidelity ideal a 1-dimensional model.

 

[sigbergaudio]

Two speakers with same on axis anechoic response will sound different depending of the room, but consider the room it cancel the term “fidelity” as one room is different from another and there’s impossible to have an ideal to replicate (except the trivial one: anechoic).

This was not the question. Do you think two different speakers with the same on axis anechoic response will measure the same off-axis?

 

[sigbergaudio]

I don’t consider spinoramas another measurement, just a graphic representation of many of on-axis ones taken on different angles.

But this is arguably wrong.

 

[Miguelón]

But this is arguably wrong.

Excuse me, just erase the word “on axis”. I was trying to say “one axis” or “one direction”

 

[Miguelón]

This was not the question. Do you think two different speakers with the same on axis anechoic response will measure the same off-axis?

I answered “no”

“Two speakers with same on axis anechoic response will sound different depending of the room”

Of course depending on the speaker, apologies again.

I basically agree with you, I take care about room response on placement, EQ and absorption materials. But this doesn’t change the measurements and instruments needed: a mic, an ADC, software analysis.

 

[Miguelón]

This was not the question. Do you think two different speakers with the same on axis anechoic response will measure the same off-axis?

When I chose my actual speakers I was considering flat response, size and active type. Two monitors accomplished that: Genelec 8030 cpm and Neumann KH120 ii.

Once listened on my room, I choice the Genelec based on how it sounded subjectively. But I didn’t consider a non-flat response active monitor as it won’t reproduce accurately some frequencies.

Many companies claim mysterious values, but nonsense to me

 

[Sal1950]

As I see it, fidelity is a useless concept for our purposes and has been for decades. It was a useful marketing term back in the day but as an engineering goal I can't see how to use it.

So you believe you can distort a signal in any way and as much as you want but as long as you like it, still call it an accurate high fidelity reproduction system?

 

[terryforsythe]

What is considered to be "high fidelity" can vary from person to person. What I consider high fidelity may be different than what you consider high fidelity. Who is wrong?

There are only subjective opinions on what is good enough, but no universally accepted specification for "high fidelity", at least that I have seen. The one definition that I have seen, I'm paraphrasing, is "faithful to the original recording". No audio system has a perfect frequency response, a perfect impulse response, and is 100% free of distortion and noise, not to mention the effect of room modes and reflections. Thus, there is no audio system that is 100% faithful to the original recording. From that perspective, there are no high fidelity audio systems in existence today.

Nonetheless, that is not the perspective that I take. My perspective is that what you consider to be an excellent sounding audio system is "high fidelity", at least to you. Others may disagree, but without a universally accepted specification as to what qualifies as high fidelity, that is just their subjective opinion, and it doesn't mean much.

 

[Sal1950]

There are only subjective opinions on what is good enough, but no universally accepted specification for "high fidelity", at least that I have seen

That is not correct.. That is "High End" audio's approach to audio so they can sell you any BS snake-oil equipment and say "it sounds good to me" so that is good enough.
Digital sources and properly designed electronics have been fully transparent to what the microphones output for decades now. The last hurtles have been speakers and the room interface which have been improved more and more each year.
SO it's your choice, you can either assemble a Hi Fi, or something else, your choice.
But what is Hi Fi by 2024 standards if very well defined.

 

[terryforsythe]

That is not correct..

Please post a link to a universally accepted specification for high fidelity.

But what is Hi Fi by 2024 standards if very well defined.

Please share the very well defined standards.

 

[Justdafactsmaam]

So you believe you can distort a signal in any way and as much as you want but as long as you like it, still call it an accurate high fidelity reproduction system?

If you are worried about the label you have lost your way

 

[Sal1950]

Please post a link to a universally accepted specification for high fidelity.


Please share the very well defined standards.

Transparent in a DBT
Start here,

Red Book CD Format Explained

The term “Red Book” is named after one of the Rainbow Books, a series of books that contain the technical specifications for all CD and CD-ROM formats.

www.travsonic.com

 

[terryforsythe]

Transparent in a DBT
Start here,

Red Book CD Format Explained

The term “Red Book” is named after one of the Rainbow Books, a series of books that contain the technical specifications for all CD and CD-ROM formats.

www.travsonic.com

Nice try, but that is a standard for CD media - "Red Book is the standard for audio CDs..." It says nothing about SNR, distortion, frequency response characteristics, impulse response characteristics, dynamic range, etc. for audio reproduction equipment.

Do you mean to infer that anything that can play a CD recorded per Red Book Audio Specifications is high fidelity?